When a marine organism once thought to be globally extinct was found in Singapore waters in 2011, marine scientists were overjoyed, twice over. They had found not one, but two neptune’s cup sponges.

Despite its size, Singapore abounds with animal and plant species. Conserving them is an ongoing challenge. In this third of a five-part series leading to Singapore Biodiversity Week starting on May 20, The Straits Times highlights a species saved from extinction: the neptune's cup sponge.
Audrey Tan Straits Times 12 May 17;

When a marine organism once thought to be globally extinct was found in Singapore waters in 2011, marine scientists were overjoyed, twice over. They had found not one, but two neptune's cup sponges.

Unfortunately, the heavily sedimented waters around Singapore allowed only one to be relocated.

However, Lady Luck smiled on them last year: the scientists rediscovered the "missing" sponge, nicknamed Neppie by the team who found it in 2011.

That is not all. They also found nearby two more individuals.
The discovery of the sponges, which resemble large wineglasses, seemed a toast to serendipity.

Said Dr Karenne Tun, director of the coastal and marine branch at National Parks Board's (NParks) National Biodiversity Centre: "We knew Neppie was about 60m away from the original sponge. So we formed a chain - five of us held on to a rope at 2m intervals, and we just swam in that direction."

Dr Tun was part of the team that discovered Neppie in 2011 and led a team of five that found it again last year. Using finstrokes to measure distance - one kick cycle was roughly 1m - the four divers from NParks and Mr Stephen Beng from the Nature Society (Singapore) swam about 60m in the waters off St John's Island without finding anything.

But at the 60m mark, Mr Beng tugged on the rope. Translation: "Sponge!" The team agreed to tug on the rope if there was good news before they descended 10m underwater. Amid circular jubilant swims around Neppie, another member of the team, Mr Koh Kwan Siong, a manager at the coastal and marine branch of NParks' National Biodiversity Centre, found two more.

More eyes underwater, favourable current conditions and good underwater visibility of about 3m that day, instead of the usual 1m to 2m, contributed to the discovery, said Dr Tun.

There are now five known neptune's cup sponges in Singapore - one more was found off Semakau Island in 2014, and moved to the Sisters' Islands Marine Park. Two more neptune's cup sponges were spotted off Singapore's southern shores, but the divers who found them did not log their exact locations.

Dr Tun hopes good visibility and more surveys of Singapore's seas would uncover the duo and, hopefully, other individuals too.

Meanwhile, NParks' goal is to see if the five sponges can help to build up the organism's population in Singapore's waters, where they were once found in abundance until overharvesting by museums and private collectors, and individuals who harvested it so they may use the cup-like structure as a bathtub for infants, nearly wiped them out.

NParks is working with researcher Lim Swee Cheng, of the National University of Singapore's Tropical Marine Science Institute, on a species recovery programme for the sponge.

Said Mr Lim: "The three discovered sponges look young. It shows larvae from this species, either from Singapore or neighbouring waters, recently settled in our waters."

But how exactly the sponges reproduce is still a mystery the scientists hope to solve through various methods, including studying its tissue to figure out when it reaches sexual maturity.

Three of the five sponges have been moved to Sisters' Islands Marine Park, and NParks plans to take the remaining two there soon. Living in close proximity gives them a better chance to reproduce and spread the eggs around Singapore waters, said Mr Lim.

"But it is also important we find out more about its life history, like when the eggs and sperm are released. Only after these studies are done, can we propagate this iconic species effectively," he added.

The scientists also discovered that the neptune's cup sponge grows fast, and had a quick rate of regeneration. Bite marks on Neppie left by turtles had been replaced with new tissue in several months. It was previously thought the sponge was likely a slow-growing species, thus contributing to its disappearance.

"Now that we know the sponge regenerates quickly, it might be possible to propagate them by taking cuttings from them - similar to how plants are propagated," said Dr Tun.

Sponges in general are natural water filters which draw in water to extract nutrients. Good sponge diversity can help to manage water quality in the reef, which provides shelter and food for other marine organisms such as fish.

Environmental group Sawit Watch is urging President Joko “Jokowi” Widodo to fulfill his pledge to declare a moratorium on the issuance of new permits for oil palm plantations, arguing that a moratorium will provide the necessary momentum to reorganize Indonesia’s palm oil industry.

The group said no progress had been made to follow up on Jokowi’s moratorium pledged in April last year, when he also promised to halt the issuance of new permits for coal mining operations.

Sawit Watch deputy director Achmad Surambo said in a press briefing on Friday that an oil palm moratorium was badly needed to stop environmental destruction in the form of land clearing for plantations.

Moreover, there was no sign that the government would revise Presidential Instruction (Inpres) No. 8/2015 on a moratorium of new permits for primary forest and peatland areas, which was due to expire on Saturday, he added.
Achmad said Inpres No. 8 and the promised oil palm moratorium were both important to ensure there would be no more land clearing for oil palm plantations. Land clearing was the prime driver of the annual land and forest fires across Indonesia.

“It will be better if Indonesia has a moratorium, as stipulated in Inpres No. 8 and another moratorium for oil palm plantations. They will complement each other,” said Achmad.

“During the moratorium, the government could revisit and then reform the management of the forests and the palm oil industry,” he went on. (ebf)

John Turner
Professor & Dean of Postgraduate Research, Bangor University

Despite extensive media coverage, campaigns and scientists’ warnings, still the world is not fully aware of what coral bleaching is and why it is happening. Mention bleaching and some think that it is the death of the Great Barrier Reef’s coral, but the problem is much more widespread.
“Bleaching” is when corals lose the highly productive algae (termed zooxanthellae) from their tissues due to stress from high sea temperatures and solar irradiation. The algae and coral have a symbiotic relationship: the algae remove the coral’s waste products while the coral gives the algae a safe environment to live in, and provides compounds for photosynthesis. Without the algae, the coral no longer has a sufficient source of food, meaning that it essentially starves to death.

Due to its iconic status and numerous nearby scientific institutes, the Great Barrier Reef often receives the most attention when it comes to coral bleaching. But there are many other reefs across the globe that are experiencing the same problem. These reef provinces encompass undeveloped, remote and unpopulated areas, where, unlike near the Great Barrier Reef, monitoring and research is either non-existent, scarce or sporadic.

Chagos reefs

The Chagos Archipelago is a British overseas territory located in the middle of the Indian Ocean, consisting of 55 islands distributed across six atolls, and covering an area the size of France. It certainly fulfils the remote criterion: the Maldives are the next island group, 300 miles to the north, and it is more than 900 miles to the more substantial landmass of the Indian subcontinent. In total, the reefs and shallow banks cover some 60,000km² – nearly three times the size of Wales.

For the past decade, we have been carrying out research in the Chagos Archipelago. What we have found is that although reefs vary in condition across the large archipelago, most were vibrant during earlier surveys and managed to rebound from the first major bleaching event in 1997/98 – when around 16% of the world’s coral was killed, and only about 10% of living coral was left to some 30m depth.

After the 2015 global bleaching event occurred, we knew that the Chagos Archipelago had been affected, but it was only during our 2016 survey that we found the bleaching had been as bad as it was in 1997/98.

A degraded reef in Chagos, pictured in April 2016.
We were struck by the stark increase in dead coral, mostly the branching Acropora which form wide table-like structures, similar to a canopy, over large portions of the reef. We found that on reefs dominated by this coral type, more than 50% of the live coral which was present in 2015 has died in shallow areas.

What is most alarming is that these surveys took place immediately before the 2016 bleaching event began in earnest, and went on to surpass 2015 in severity. The true condition of the reefs within the Chagos Archipelago at present is unknown, as we haven’t yet been able to revisit the study sites.

Hat-trick events

We also don’t know when, or if, a 2017 bleaching event will occur on the Chagos Archipelago. But based on global sea temperature patterns so far, and early indications of bleaching starting on the Great Barrier Reef – which usually precedes events in the Indian Ocean – a 2017 event could begin in a matter of weeks.

This could very well be the start of a new era for the coral reefs of the Indian Ocean and beyond. Of course, bleaching itself is not a new phenomenon, having been first recorded in 1911 in the Florida Keys, and is likely to have occurred, certainly at local scales, throughout the last several millennia of global reef growth. What is completely new, however, is this frequency of bleaching events: if a 2017 event materialises it will be part of an unprecedented “hat-trick” of yearly back-to-back mass coral bleachings. Corals may recover from mild and infrequent bleaching events, but will die from severe and repeated loss of their algal symbionts.

Scientists warned in 1999 that if global warming patterns continued, reefs in the Indian Ocean could start to bleach every five to 10 years by 2010. Unfortunately, it appears these predictions have been met and may even be surpassed in the next decade.

Reducing the impact

There is no easy way to stop coral bleaching. A frequent suggestion is to focus on removing localised impacts and stressors such as over-fishing and excess nutrient inputs from agriculture. However, the Chagos islands are already devoid of these pressures, and yet appear to be equally susceptible to the effects of global warming as more populated reef areas.

Though we don’t know if these reefs can bounce back from bleaching, based on the previous pattern following the 1998 global bleaching event – where up to 90% of corals died in some parts of the Chagos Archipelago – the reefs could take a decade or more to recover. But if these yearly repeat bleachings carry on, it could be like pressing the reset button on each trajectory of recovery just as it gets underway.

Nonetheless, it could be argued that if anywhere has a chance of recovery the Chagos Archipelago does, and by continuing to research this location we may learn more about what factors promote and drive reef recovery in the process.